The Children's Hospital of Philadelphia (CHOP) proposes to continue the NICHD-sponsored Child Health Research Career Development Award (CHRCDA) K12 Training Program. Our goal is to increase the number and effectiveness of subspecialty pediatricians with a rigorous background and skills in molecular techniques by identifying and training promising pediatric faculty to become successful physician-scientists, and to encourage them to address questions of fundamental importance to health and disease in children. Candidates for our program will be primarily CHOP junior faculty, appointed from our subspecialty fellowship programs, who are identified through national searches for the best and the brightest. Each candidate will identify a prospective mentor from a group of 38 mentors, 34 from CHOP (Pediatrics, Pathology, Surgery) and 4 from the University of Pennsylvania (Penn). These CHOP-CHRCDA mentors were chosen by the following criteria: rigorous science in areas germaine to pediatrics, a record of successful mentoring and collaborative research interactions, strong record of extramural funding, and programmatic balance. In general, Pediatric Scholars will be supported for two years to conduct research as outlined in their formal research applications. They will have ready access to a comprehensive array of research core laboratories, and they will have ample opportunity to exchange ideas in both formal and informal settings with senior and other junior investigators. We view the CHRCDA as a natural successor to our prior Child Health Research Center (CHRC) grant: Molecular Approaches to Pediatric Science (MAPS), which was highly successful in catalyzing the production of physician-scientists capable of conducting fundamental, independent research. In the past 14 years, we have identified and trained 47 Pediatric Scholars from a wide range of subspecialties. This continuation of our CHOP-CHRCDA will build on the tradition of our MAPS grant and the first four years of our CHRCDA, taking advantage of the tremendous strengths of CHOP as an academic pediatric institution with an outstanding pool of subspecialty fellows, a large number of experienced mentors, and cutting edge research programs. CHOP and Penn provide a very comprehensive, well-supported and resource-intense environment, as well as a proven track record of training basic and translational academic investigators.